An oscilloscope is a type of electronic instrument for graphically displaying measured electrical parameters, such as voltage. Typically, an oscilloscope's graphical display includes a two-dimensional plot of the electrical parameter versus time.
Originally, oscilloscope were analog devices, which displayed their graphics on a cathode ray tube (CRT). Newer types of oscilloscopes are digital. For example, a digital storage oscilloscope (DSO) can convert analog signals to digital form, store those signals, and process the signals for display, typically on a liquid crystal display (LCD) device.
DSOs having two channels are known. Each channel of a DSO drives trigger comparators to support advanced triggering modes, such as runt, window and transition time triggering.